Spinal locking sleeve assembly

ABSTRACT

The present invention relates to a locking sleeve assembly for use in a posterior spinal system including components designed to be affixed to the spinal column of a person to correct for various lateral and sagittal deformities. The locking sleeve assembly is for interconnecting an elongated rod with another structure. The locking sleeve assembly includes an elongated sleeve having a bore therethrough. The sleeve has a tapered first end and a second end having a lock member thereon. The sleeve includes at least one split extending into the sleeve. The bore is sized to slidably receive the rod. The tapered surface of the sleeve is insertable into a tapered passage of the other structure with the rod in the bore, to form an interference fit between the two tapered surfaces. The locking sleeve assemblies are used in conjunction with the spinal system which also includes a pair of smooth surfaced rods mounted in spaced relation to one another on the spinal column in conjunction with various fixation devices such as clamps with hook bodies, hooks, screws with hook bodies, and couplers. Each such fixation device utilizes locking sleeve assemblies at each connection point to secure the respective fixation device to the respective rod or rods. The coupler assemblies are provided to maintain the spacing of the rods. The method of performing surgery using the posterior spinal system is also disclosed.

This is a division of application Ser. No. 07/287,245 filed Dec. 21,1988, now U.S. Pat. No. 5,074,864.

BACKGROUND OF THE INVENTION

The present invention relates to a posterior spinal system and method.In the prior art, posterior spinal systems are known. These systemsinclude various appliances interconnected together to correct spinalcolumn deformities.

In prior art systems, however, problems have developed, particularly asto the ability of the spinal rods to withstand the stresses placedthereon and as to the ability to mount various fixation appliances onthe rods and maintain them in a desired position and orientation withrespect thereto.

It has been found that modifications from a smooth surfaced rod, suchas, for example, knurling or threading of the surface or providingratchets along the rod, inherently result in weakening of the strengthof the rod by creating stress risers for crack initiation on the outersurface of the rod. It is further noted, for example, that a knurled rodwould need a larger diameter to provide comparable strength to acorresponding unknurled or smooth rod of smaller diameter.

Furthermore, it has been found that requiring a surgeon to pre-mount thevarious appliances on the rods, as may be required when threaded rodsare used, is an inconvenient surgical technique, since if the surgeonmiscalculates and needs to add or remove various appliances to or fromthe rods, complications in surgery result, since the surgeon must removethe rods from the patient after they have already been placed in situfor the purpose of unthreading or threading, appliances, therefrom orthereto.

As such, a need has developed for a posterior spinal system having rodsof increased strength and having attachment means designed to be used toattach the various appliances on the rod without the need forpre-assembly prior to placement of the rod.

The following prior art is known to applicants:

U.S. Pat. No. 4,202,644 to Soussloff discloses a mounting devicedesigned to be used to mount a machine element on a rotary shaft. Thedevice used two interlocking split sleeves with the inner sleeve havinga threaded end engaged by a threaded member coupled to the outer sleeve,with rotations of the threaded member causing movement of the sleeveswith respect to one another which, due to their interface which includesconical surfaces, causes an increase in the diameter of the combinedsleeves to cause a wedging of the shaft into an opening on the machineelement. This is different from the teachings of the present inventionwherein a locking sleeve assembly is provided which uses a single sleevehaving a tapered outer surface and a threaded end and wherein a lock nutis threaded over the threaded end and has a flange to bear against aside surface of an element which is to be locked onto a smooth shaftinserted through the sleeve.

U.S. Pat. No. 4,629,178 to Keene discloses an open back hook assemblyfor engaging a spinal column which includes the provision of a threadedrod to which respective sleeves and nuts are threadably mounted. Hooksare affixed to the rod by sliding them over the sleeves and tighteningthe respective nuts. This is different from the teachings of the presentinvention wherein the rods themselves are smooth throughout theirlengths and connection of hooks or other fixation structures thereto isaccomplished by wedging action between the hooks or other componentswith corresponding locking sleeve assemblies to secure them to therespective rod. Connector assemblies may be utilized between the rodsThus, the present invention has advantageous aspects over and above theteachings of Keene by providing a smooth surfaced rod which isinherently stronger than a threaded rod, and by providing a lockingsleeve assembly which allows easier placement and removal of hooks orother components therefrom.

U.S. Pat. No. 4,274,401 to Miskew discloses an apparatus for correctingspinal deformities and the method of using the apparatus. In eachembodiment of Miskew, the rod which is employed has either a threadedsurface or a surface including a plurality of adjustment stop surfaces(FIG. 25). This is different from the teachings of the present inventionwherein rods with smooth surfaces are employed as well as otherdistinctions.

U.S. Pat. No. 4,361,141 to Tanner discloses a scoliosis transversetraction assembly which acts as a tensioning device to maintain twospaced rods in position with respect to each other. The tensioningdevice includes a transverse threaded rod with a basket hook at one endand a transverse hook toward the other end. The position of thetransverse hook is adjustable along the transverse rod. This isdifferent from the turn-buckle-type coupler of the present invention.

U.S. Pat. No. 4,567,884 to Edwards discloses a spinal hook designed tobe used with a spinal correction system, which system includes boththreaded rods and rods with projecting annular surfaces (ratchets)thereon. The hooks of Edwards may be modified for use with the presentinvention by incorporating an open back and further adapting the hook toaccept the locking sleeve of the present invention. However, the presentinvention is distinct from the teachings of Edwards.

U.S. Pat. No. 4,611,582 to Duff discloses a vertebral clamp designed tobe used between two adjacent vertebrae through attachment to the laminaethereof. The clamp includes two clamp members, one for each vertebra anda threaded coupling member designed to be used to adjust the distancebetween the clamps to achieve the desired spacial relationship. Incontrast with this teaching, the present invention includes mid-lineclamps which may be used to fix the position of elongated smoothsurfaced rods on the posterior spine.

U.S. Pat. No. 4,641,636 to Cotrel discloses a device for supporting therachis which includes the use of both closed and open back hookssupported on a rod having a knurled surface defined in this patent ashaving "a multitude of aspirates 21, obtained for example by milling orturning." A screw member 25 is utilized to secure the hooks to theknurled rod. This is different from the teachings of the presentinvention wherein smooth surfaced rods are employed as well as otherdistinctions.

French Patent No. 2,151,475 to Cotrel discloses a spinal appliancedesigned to be attached between two greatly spaced points on a spinalcolumn as best seen in FIG. 7 through the use of end hooks. This isdifferent from the teachings of the present invention wherein a desiredcurvature of the spine may be obtained by pre-bending a pair of smoothsurfaced rods and affixing a plurality of components and appliancesthereto to achieve a separation between the rods, as well as a desiredconfiguration of the spine.

French Patent No. 2,244,446 to Cotrel discloses a transverse threadedrod to maintain two spaced spinal rods (one a ratcheted rod and one athreaded rod) in spaced relation with respect to each other. This isdifferent from the turnbuckle-type coupler assembly of the presentinvention. Other distinctions also exist including, for example, the usein the present invention of smooth surfaced rods.

Zimmer Publication titled "Edwards Spinal Fixation System", 1984,discloses a spinal system developed in conjunction with Dr. Charles C.Edwards, including rods, sleeves and hooks. The sleeves (also describedby U.S. Pat. No. 4,369,769 to Edwards) act as spacers between the spinalrod and the spine. The Edwards Anatomic Hooks shown in this publicationcorrespond to the above-mentioned U.S. Pat. No. 4,567,884 to Edwards.

Zimmer Publication titled "Interspinous Segmental SpinalInstrumentation: Surgical Technique", by Dr. Denis S. Drummond and JamesKeene, 1984, discloses instruments and appliances used in performingspinal surgery. The system utilizes a paired, button/wire implant inwhich wires are tied to various types of spinal rods. The presentinvention does not utilize such a button/wiring technique.

Zimmer Publication titled "KNODT Distraction-Fusion Instrumentation",1980, discloses the use of hooks mounted on threaded shafts designed toseparate adjacent vertebrae from one another by a predetermineddistance. This is different from the teachings of the present inventionwhich uses open-backed hooks as well as smooth surfaced rods.

Zimmer Publication titled "Luque Segmental Spinal InstrumentationSurgical Technique", 1980, discloses segmental spinal instrumentationdeveloped in conjunction with Dr. Edwardo R. Luque. In the Luque systemand technique, elongated rods are used along with twisted wiring to holdthe smooth rods in the desired spaced relation. This is different fromthe teachings of the present invention which does not utilize such awiring technique.

Zimmer Publication titled "Wisconsin Compression System", discloses theuse of prior art, Harrington, Keene and Drummond systems. The Keene hookdisclosed in U.S. Pat. No. 4,269,178, discussed above, is employed andthe use of threaded rods as well as rods having consecutive projections(ratchets) thereon is disclosed. The teachings of the present inventionare distinct from the teachings of this publication, as including theuse of rods which are smooth surfaced and wherein split sleeve lockingassemblies are used to hold the various components on the rods.

An article entitled "A Locking Hook Spinal Rod System For Stablizationof Fracture-Dislocations," Jacobs et al, Clinical Orthopaedics andRelated Research, No. 189, October 1984, pp. 168-177, discloses a spinalsystem which utilizes a locking cover to secure the lamina in the hookand meshing radial grooves to lock the contoured rod to the upper andlower hooks. This is different from the smooth rod, open back hook andlocking sleeves of the present invention.

SUMMARY OF THE INVENTION

The present invention relates to a locking sleeve assembly for use in aposterior spinal system and method. The locking sleeve assembly is forinterconnecting an elongated rod with another structure. The lockingsleeve assembly includes an elongated sleeve having a bore therethrough.The sleeve has a tapered first end and a second end having a lock nutthereon. The sleeve includes at least one split extending into thesleeve. The bore is sized to slidably receive the rod. The taperedsurface of the sleeve is insertable into a tapered passage of the otherstructure with the rod in the bore, to form an interference fit betweenthe two tapered surfaces. The sleeve assembly will be described inconjunction with the spinal system in order to provide an understandingof the clamp in conjunction with such a system. The inventive systemincludes the following aspects and features:

(a) In a first aspect of the present invention, the entire systemrevolves about the use of elongated rods with smooth surfaces throughouttheir respective lengths. Smooth, for the purposes of this application,is defined to be the absence of purposeful machining operations, such asthreading, knurling, ratcheting or the like. However, smooth for thepurposes of this application, could include polished surfaces as well assurfaces resulting from processes such as turning, grinding, forging andcasting and could include light surface preparations such as dryblastings, shot peening or the like. As noted hereinabove, applicantshave found that whenever the surface of an elongated rod is modifiedthrough knurling, threading, ratcheting or the like, the strength of therod is weakened. As such, in order to maximize the strength of theinventive system, the rods used therein have smooth surfaces throughouttheir lengths.

(b) A plurality of different appliances and components are used in theinventive system and central to the inventive system is the manner ofassembly of these various appliances and components to theabove-described smooth surfaced rods. This manner involves the use of alocking sleeve assembly at each connection point of a respectiveappliance and/or component to a respective rod.

(c) Each locking sleeve assembly includes an elongated sleeve having oneend which is tapered and another end which is threaded. A plurality ofcircumferentially-spaced angularly related splits are provided throughthe sleeve to allow the sleeve to be compressed. One of these splitsextends the entire length of the sleeve. A lock nut may be threaded overthe threaded end of the sleeve, which lock nut includes a radiallyoutwardly extending flange. The sleeve has an opening therethroughdesigned to slidably receive a smooth surfaced rod. In the operation ofthe locking sleeve assembly, when it is desired to attach an applianceor component to a smooth surfaced rod, the sleeve is placed over the rodand the appliance or component is mounted on the sleeve over the taperedend thereof. As the lock nut is threaded over the threaded end of thesleeve, eventually, the flange thereof will engage a sidewall of theappliance or component to thereby cause the tapered end to be pulledthrough the opening in the appliance or component so that a wedginginteraction therebetween is created to thereby cause the tapered end ofthe sleeve to frictionally engage the internal tapered walls of theopening in appliance or component while the splits in the sleeve allowthe sleeve to be squeezed in frictional attachment over the rod.

(d) A further component forming a part of the inventive system consistsof various styles of open back spinal hooks each hook having a shoe (orhook end portion) attached to a body having an open back allowingattachment over the tapered end of the sleeve of the locking sleeveassembly described hereinabove. The spinal hook may be attached on arespective smooth surfaced rod in the manner described in paragraph (c).Many styles of spinal hooks can be adapted or modified to incorporatethe open back features for use with the locking sleeve assembly of thepresent invention. Examples of such hooks which can be adapted toincorporate such features are bifid hooks, Andre hooks, "lamina" orEdwards hooks as well as others.

(e) A further component forming an integral part of the inventive systemis termed a "mid-line clamp assembly" and is designed to be centrallymounted in vertical orientation on the posterior spine. The mid-lineclamp assembly, in the preferred embodiment thereof, may be made in twosizes, termed small and large. Each clamp assembly includes two shoes,each of which is mounted on a respective clamp half with the clamphalves being mounted together in a sliding interconnection. Therespective clamp halves and shoes are termed "superior" and "inferior".In the small clamp assembly, the inferior clamp half has a single studextending perpendicularly therefrom, as does the superior clamp half. Inthe large mid-line clamp assembly, each of the clamp halves is moreelongated than is the case in the small mid-line clamp assembly, and inthe large mid-line clamp assembly, the superior clamp half has twospaced such studs.

(f) The mid-line clamp assemblies are incorporated into the inventivesystem, in assembly, through the use of open-backed hook bodies. Eachsuch hook body includes a circular recess designed to detachably receivea respective stud from a respective clamp half of a clamp assembly andfurther includes an open back allowing placement over the tapered end ofa sleeve of a locking sleeve assembly. Once the lock nut of the lockingsleeve assembly has been threaded to a position wherein the flangethereof engages a sidewall of the hook body to thereby pull the taperedend of the sleeve thereof through the open backed portion of the hookbody to thereby lock the hook body in mounted position on a smoothsurfaced rod, the above-described stud will also be locked in thecircular recess against removal until such time as the hook body isremoved from the locking sleeve assembly. The circular recess of theopen backed hook body is sized to also receive the stud like head of apedicle screw (not shown). Again, when the open backed hook body ismounted on the smooth surfaced rod by virtue of operation of a lockingsleeve assembly, the pedicle screw may not be removed from the circularrecess thereof.

(g) In the intended mode of use of the inventive system, a pair ofsmooth surfaced rods are mounted on the posterior spine through the useof the above-described appliances and components. In order to completethe assembly of the inventive system on the posterior spine, it isnecessary to maintain the space of the two smooth surfaced rods from oneanother, thus increasing stability. For this purpose, coupler assembliesare provided each of which includes a pair of open backed bodies whichmay be moved toward and away from one another by virtue of a turnbuckledevice. Each of the respective bodies may be mounted over a respectivesmooth surfaced rod through the use, in each case, of a locking sleeveassembly in the manner described in detail hereinabove. With suchmounting having taken place, the turn buckle device may be rotated toadjust the spacing between the bodies of the coupler assembly.

In the practice of surgery, using the posterior spinal system of thepresent invention, the following steps may be undertaken:

(1) First, the site is prepared through performance of an incisionfollowed by prepping of sites for hooks and mid-line clamps. Spinousprocess carpentry or controlled cutting of the bone is undertaken whererequired to prep the various portions of the spinal column for receiptof the clamps.

(2) The various hooks and clamps are placed in position at the preppedsites.

(3) The smooth surfaced rods are contoured using rod bending means tothe normal contours of the spinal column for the particular individualon whom the surgery is being performed.

(4) Thereafter, locking sleeve assemblies are mounted on the rod and areplaced at or adjacent the appropriate positions with respect to thepositions of the hooks and clamps as placed in position.

(5) The hooks and/or clamps are mounted on the rods through the use ofthe locking sleeve assemblies and the coupler assemblies are mounted onthe rod via locking sleeve assemblies to define the spacing between therods.

(6) Thereafter, the site is closed through the use of standard surgicaltechniques.

(7) Of course, as should be understood by those skilled in the art,additional components may be used in conjunction with techniquedescribed above, such as, for example, pedicle screws. Of course,depending upon the particular situations involved, either large or smallmid-line clamp assemblies, or both, may be employed.

The inventive posterior spinal system is designed for use in treatingidiopathic scoliosis, thoracolumbar fractures and kyphosis. Lateralcorrection, de-rotation and establishment of sagittal plain contours maybe accomplished via nodal approximation. Both distraction andcompression may be simultaneously employed on the same rod.

Accordingly, it is a first object of the present invention to provide aposterior spinal system and method of use thereof.

It is a further object of the present invention to provide such aposterior spinal system which uses rods having smooth surfacesthroughout to increase strength and flexibility thereof.

It is a yet further object of the present invention to provide such aposterior spinal system with locking sleeve assemblies designed to beused to removably attach all components and assemblies to the smoothsurfaced rods thereof.

It is a yet further object of the present invention to provide such aposterior spinal system which may include hooks, clamps, screws andother methods of spinal attachment.

It is a yet further object of the present invention to provide a methodof performing surgery using the posterior spinal system of the presentinvention.

These and other objects, aspects and features of the present inventionwill be better understood from the following detailed description of thepreferred embodiments when read in conjunction with the appended drawingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 7 show two examples of a spinal column having examples ofthe inventive posterior spinal system mounted thereon. As seen in FIGS.1 and 7, a spinal column 1 includes cervical vertebrae 2, thoracicvertebrae 3, lumbar vertebrae 5 and the sacrum 7.

FIG. 1 shows a posterior view of a human spinal column with a firstexample of the inventive posterior spinal system affixed thereto.

FIG. 2 shows a cross-sectional view along the line 2--2 of FIG. 1.

FIG. 3 shows a cross-sectional view along the line 3--3 of FIG. 1.

FIG. 4 shows a cross-sectional view along the line 4--4 of FIG. 1.

FIG. 5 shows a cross-sectional view along the line 5--5 of FIG. 1.

FIG. 6 shows a cross-sectional view along the line 6--6 of FIG. 1.

FIG. 7 shows a posterior view of a human spinal column having a secondexample of the inventive posterior spinal system affixed thereto.

FIG. 8 shows a cross-sectional view along the line 8--8 of FIG. 7.

FIG. 9 shows a cross-sectional view along the line 9--9 FIG. 7.

FIG. 10 shows a cross-sectional view along the line 10--10 of FIG. 7.

FIG. 11 shows an enlarged view of a portion of FIG. 1.

FIG. 12 shows a perspective view of a lamina hook which forms a part ofthe inventive system.

FIG. 13 shows a perspective view of a bifid hook which forms a part ofthe inventive system.

FIG. 14 shows a perspective view of a large mid-line clamp assemblywhich forms a part of the inventive system.

FIG. 15 shows a cross-sectional view along the line 15--15 of FIG. 11.

FIG. 16 shows an exploded perspective view of a locking sleeve assemblywhich forms a part of the inventive system.

FIG. 17 shows a cross-sectional view along the line 17--17 of FIG. 11.

FIGS. 18, 19, 20, 21 and 22 show views from various perspectives of ahook body which forms a part of the inventive system.

FIG. 23 shows a side view of a coupler assembly which forms a part ofthe inventive system.

FIG. 24 shows an exploded bottom view of the coupler assembly.

FIG. 25 shows a cross-sectional view from the side, of the inventivecoupler assembly.

FIG. 26 shows a side view of an Andre hook which is included in theinventive system.

SPECIFIC DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 7 show two examples of the use of the inventive posteriorspinal system.

FIG. 1 shows a pair of rods 10, each of which has a smooth surface 11throughout its length. The rods 10 are affixed in spaced relation withrespect to one another by virtue of a plurality of mid-line clamps 20and coupler assemblies 60. The mid-line clamps 20 and coupler assemblies60 are affixed to the rods 10 through the use of locking sleeveassemblies 100, with the mid-line clamps 20 utilizing hook bodies 140interposed between the respective mid-line clamps 20 and locking sleeveassemblies 100.

In the example of FIG. 7, the rods 10 have smooth surfaces 11 throughouttheir lengths and are mounted on the spinal column in fixed relationshipwith respect to one another through the use of the coupler assemblies 60as well as through the use of bifid hooks 180 and lamina hooks 220. Thecoupler assemblies 60 and hooks 180, 220 are coupled to the rods 10through the use of locking sleeve assemblies 100.

With reference, now, to FIGS. 16 and 17, a locking sleeve assembly 100is seen to include an elongated sleeve 101 and lock nut 103. The sleeve101 includes one end 105 having a surface 107 which tapers downwardly toa termination at a shoulder 109 from which extends another end 111 ofthe sleeve 101 which another end 111 includes screw threads 113throughout its length.

A plurality of splits 115 are formed at an oblique angle to thelongitudinal direction of elongation of the sleeve 101 with the splits115 terminating just short of the end 117 of the sleeve 101. Suchtermination of the splits 115 maintains the structural integrity of thesleeve 101. However, one of these splits 115 may extend the entirelength of the sleeve 101. It is advantageous for the slits to be angledobliquely to reduce the risk of having the land between two adjacentslits from being exposed at the opening of the open-back hook or hookbody.

The lock nut 103 includes a threaded passageway 121 therethrough withits outer surface consisting of a preferably hexagonally-shaped outersurface 123 and a radially outwardly extending flange 125.

With reference back to FIG. 17, sleeve 101, it should be understood thatthe surface 107 has a slight frustoconical taper which increases indiameter in a direction away from the threaded portion 111 thereof.

In the preferred embodiment of the present invention, the sleeve 101includes three circumferentially-spaced splits 115, as illustrated, forexample, in FIGS. 3 and 4.

As should be understood from the above description, the locking sleeveassembly 100 is advantageous in fixing the position of a component on asmooth surfaced rod 10. With reference to FIGS. 16 and 17, it should beunderstood that when a component is placed over the tapered surface 107,which component has a correspondingly tapered recess with an internaldimension smaller than the outer diameter of the surface 108 of thesleeve 101, when the locking nut 103 is threaded onto the threads 113 ofthe sleeve 101, and the flange 125 thereof bears against a sidewall ofthe component, such interaction causes interengagement of the taperedsurface 107 of the sleeve 101 with tapered inner surfaces of the recessin the component (not shown in FIGS. 16 and 17) to thereby cause awedging action which not only causes frictional retention of the surface107 of the sleeve 101 on the inner surfaces of the recess of thecomponent, but also causes compression of the sleeve 107, due to theexistence of the splits 115 thereof to cause the inner surfaces 110 ofthe sleeve 101 to frictionally grip the smooth surface 11 of the rod 10to thereby cause simultaneous retention of the locking sleeve assembly100 in fixed relation on the rod 10 with a component mounted in fixedrelation on the locking sleeve assembly 100. One example of a degree oftaper which has been found appropriate for the surface 107 and therecess in the component is about 6 degrees from the longitudinal axisthereof. This interaction will be better understood from the descriptionherein below of such figures as, for example, FIGS. 2, 4, 11, 12 and 13.

With reference, now, to FIGS. 12, 13 and 26, three examples of hookswhich form a part of present invention are shown.

FIG. 12 shows a lamina hook 220 which includes a body 221 and a shoe 223which forms a hook. The body 221 includes a recess 225 having an arcuatewall 227 with an opening 229, opening in a direction facing away fromthe shoe 223.

The arcuate wall 227 is tapered from a smaller diameter at the referencenumeral 231 to a larger diameter adjacent the reference numeral 233.However, it is noted that a taper in the reverse direction (not shown)could also be utilized, if desirable. If desired, recesses 235 may beprovided in the body 221 of the hook 220 to facilitate gripping of thehook 220 by a suitable instrument.

The shoe portion 223 of the lamina hook 220 includes a first leg 224extending substantially perpendicularly to the direction of longitudinalelongation of the recess 225 of the body 221 of the hook 220, as well asa second leg 226 which is substantially perpendicular to the leg 224.The end 228 of the second leg 226 extends beyond the end 223 of the body221, as best seen in FIG. 10. As further seen in FIG. 10, the laminahook 220 is affixed to the rod 10 via a locking sleeve assembly 100. Thetapered surface 107 of one end 105 of the sleeve 101 is seen in phantomin FIG. 10, as is the tapered surface 227 of the recess 225 of the hook220. As should be understood from FIG. 10, when the flange 125 of thelocking nut 103 of the locking sleeve assembly engages the surface 231of the hook 220, further rotation of the locking nut 103 with respect tothe sleeve 101 will result in pulling of the end 105 of the sleeve 101upwardly in view of FIG. 10 through the recess 225 in the body 221 ofthe hook 220 to thereby cause (1) wedging action between the surfaces107 and 227, as well as (2) squeezing of the inner surfaces 110 of thesleeve 101 against the smooth surface 11 of the rod 10, to therebyrigidly affix the hook 220 thereon.

FIG. 13 shows a bifid hook 180 having a body 181 and a shoe portion 183forming a hook. The body 181 includes a recess 185 having inner surfaces187 the terminations of which define an opening 189. The surfaces 187 ofthe recess 185 taper from a smaller diameter at the end 191 to a widerdiameter at the end 193. Again, it is noted that a taper in the reversedirection could also be utilized if desirable.

The shoe portion includes a first leg 184 and a second leg 186 attachedthereto which leg 186 is bifurcated to form a recess 188 which separatestwo legs 190, 192.

As best seen in FIG. 9, the legs 184, 186 form a substantiallycontinuous curve as opposed to the angular relationship between the legs224 and 226 of the lamina hook 220, best seen in FIG. 10.

The manner of fixation of the bifid hook 180 to the rod 10 is analogousto the manner of fixation of the lamina hook 220 to the rod 10, asexplained herein above with reference to FIGS. 10 and 12 in particular.

With reference to FIG. 26, a further hook termed an Andre hook isgenerally designated by the reference numeral 200 and is seen to includea body 201 and a shoe portion 203.

The body 201 includes a recess 205 seen in phantom, including recesswalls 227 which taper from a smaller diameter adjacent the wall 211 tolarger diameter adjacent the wall 213. An opening (not shown) in therecess 205 is analogous to the respective openings 229, 189 of therespective lamina hook 220 and bifid hook 180.

The shoe portion 203 includes a first leg 204 and a second leg 206 whichare connected together in a continuous curve which differs from the shoeportion of the bifid hook 180, in that the terminus of the leg portion206 faces toward the body 201 of hook 200, as seen in FIG. 26, asopposed to the configuration of the leg 186 of the bifid hook 180 whichfaces away from the body 181.

The manner of attachment of the Andre hook 200 to a smooth surfaced rod10 is the same as the manner of installation of the respective bifidhook 180 and lamina hook 220.

In each hook, the open backed portion is widened at the widest end ofthe recess thereof to best facilitate the insertion of a sleeve 107therein. This aspect is designated by the reference numerals 222 (FIG.12) and 182 (FIG. 13).

With reference, now, to FIGS. 11, 14 and 15, embodiments of a mid-lineclamp assembly will be described in detail. With reference, first, toFIGS. 11 and 15, a small mid-line clamp assembly 20 is seen to includean inferior clamp half 23 and a superior clamp half 25. The inferiorclamp half 23 includes a body 27 with a shoe 29 at one end thereof, anda transverse inferior stud 31 extending outwardly from an opposite endthereof.

The superior clamp half 25 includes a body 33 with a shoe 35 at one end,and a transverse superior stud 37 extending outwardly from an oppositeend thereof. As should be understood from the analogous structuredesignated by the respective reference numerals 269 and 275, the shoes29 and 35 are of hook-like configuration.

With particular reference to FIG. 15, it is seen that the body 33 of thesuperior clamp half 25 includes a recess 39 of L-shaped cross-section inwhich is slidably received a rib 41 of L-shaped cross-section having aneck portion 43 and a cross piece 45. The interaction between the recessand the rib allows easy sliding movement between the superior clamp half25 and the inferior clamp half 23. It is understood that other slidablemating shapes could be utilized, such as a T-shaped cross-section, adovetail-shaped cross-section, or any other suitable configuration.

With reference to FIG. 14, a large mid-line clamp assembly 260 isillustrated which is quite similar to the small mid line clamp assembly20 best illustrated in FIGS. 11 and 15. The main difference between thelarge mid-line clamp assembly 260 and the small mid-line clamp assembly20 lies in the fact that the clamp halves of the large mid-line clampassembly 260 are elongated as compared to the respective lengths of theclamp halves of the small mid-line clamp assembly 20. Additionally, dueto this elongation, the superior clamp half 265 of the large mid-lineclamp assembly 260 has the provision of two spaced transverselyextending studs 277 and 278.

With particular reference to FIG. 14, it is seen that the large mid-lineclamp assembly 260 includes an inferior clamp half 263 and a superiorclamp half 265. The inferior clamp half 263 includes a body 267 and ashoe 269 of hook-like configuration. As is seen in FIG. 14, the inferiorshoe 269 is significantly wider than the superior shoe 275.

The superior clamp half 265 includes a body 273 and a shoe 275 ofhook-like configuration. The clamp halves 263 and 265 are slidablyconnected to one another through the recess and L-shaped ribconfiguration best illustrated in FIG. 15 with regard to the smallmid-line clamp assembly 20 and designated therein by the referencenumerals 39, 41.

The inferior clamp half 263 has incorporated therewith a transverseoutwardly extending stud 271 on an end of the body 267 thereof opposedto the end on which the shoe 269 is formed. The superior clamp half 265includes two, spaced transversely extending studs 277 and 278 with thestud 278 lying adjacent the shoe 275 and with the stud 277 being locatedtoward an end of the body 273 of the superior clamp half 265 opposed tothe end on which the shoe 275 is formed. The inclusion of two studs, 277and 278 on the superior clamp half 265 is provided to add versatility inthe mounting of the large mid-line clamp assembly 260 on the posteriorspine.

As is the case with the other components described herein above, theclamps 20 and 260 are removably attachable to respective smooth surfacedrods 10 through the use of locking sleeve assemblies. The studs areprovided to facilitate this attachment of the clamp assemblies withrespect to the smooth surfaces rods 10. Interposed between therespective studs and the respective rods are hook bodies 140, an exampleof which is illustrated in FIGS. 18-22.

With reference to FIGS. 18-22, the hook body 140 is seen to include anopen back 141 leading to a recess 143 which is tapered from a largerdiameter adjacent a wall 145 to a smaller diameter adjacent a wall 147.With particular reference to FIG. 22, an opening 142 is provided througha wall in the hook body 140 for the purpose of allowing the gripping ofthe hook body 140 by a suitable surgical instrument.

Intersecting the recess 143 and the wall 145 is a further recess 149having curved walls 151 and an opening 153 at its junction with the wall145. The recess 149 is sized and configured to receive one of thetransverse studs of a mid-line clamp assembly. The recess 143 is sizedand configured to be mountable over the tapered surface 107 of the end105 of the sleeve 101 of a locking sleeve assembly 100.

A respective stud is inserted into a respective recess 149 through theopening 153 thereof, and after the hook body 140 has been securelymounted over a locking sleeve assembly 100, as should be understood fromthe above detailed description of such procedure, the said stud iscaptured in the recess 149 and may not be removed therefrom until thelocking sleeve assembly 100 is subsequently loosened. This is the casebecause, with reference to FIG. 11, each stud has a narrowed neck 900allowing the stud to be pushed inwardly in the recess 149 to allowremoval of the stud therefrom. Intrusion of the end 105 of the sleeve101 of the locking sleeve assembly 100 into the recess 143 of the hookbody 140 prevents the inward movement of the stud which is necessary toallow its removal from the recess 149. Thus, this interaction of partsallows a secure assembly of a respective stud on a hook body 140.

As should be understood with reference to FIG. 11, two hook bodies 140are used in conjunction with locking sleeve assemblies 100 and rods 10to secure each mid-line clamp in assembled relation on the thoracic orlumbar lamina.

As seen with reference to FIGS. 5, 6 and 11, the hook bodies 140 areoriented in opposed directions on the respective smooth surfaced rods 10and are attached thereto by virtue of locking sleeve assemblies 100 alsomounted in opposed directions in a manner such that the studs 31 and 37are captured by the respective recesses 149 in a manner opposingmovement of the shoes 29, 35 away from one another. Thus, the clampassembly 20 is initially placed over the mid-line of a thoracic orlumbar lamina and the bodies 27, 33 are slid with respect to one anotherto cause the shoes 29 and 35 thereof to grip both surfaces of thelamina. With the clamp assembly 20 held in such position, hook bodies140 are attached over the respective studs 31 and 37 and are fastened inplace through the use of locking sleeve assemblies 100 to maintainfixation of the mid-line clamp assembly 20 over the lamina and withrespect to the two smooth surfaced rods 10.

The same procedure would be followed in placing and securing a largemid-line clamp assembly 260 over the lamina of a thoracic or lumbarvertebra and for the fixation thereof with respect to two smoothsurfaced rods 10.

As has been explained hereinabove, it is desirable to provide some meansfor maintaining the spacing between two smooth surfaced rods 10 from oneanother to increase the stability of the system. For this purpose,coupler assemblies 60 are provided, as seen in FIGS. 1 and 7, tomaintain the desired separation between the rods 10. An example of asuch coupler assembly is seen in FIGS. 3, 4, 23, 24 and 25.

With reference to FIGS. 23-25, the coupler assembly 60 is seen toinclude a first body 61, a second body 63 and a sleeve 65.

The body 61 includes an open backed retainer or head 67 and a rod orshaft 69 having right-hand threads 71 thereon. A short, narrowed neck 68interconnects the rod 69 and the retainer 67.

With further reference to FIGS. 24 and 25 in particular, the body 63includes an open backed retainer 73, a rod 75 having a smooth outersurface 76 and a neck 77 having left-hand threads 79 thereon. The rod 69of the body 61 includes a central blind bore 70 therein which is sizedto slidably receive therein the rod 75 of the body 63.

The sleeve 65 includes a central bore 81 which terminates at one endwith a short band of right-hand threads 83 and at the other end by ashort band of left-hand threads 85.

With further reference to FIGS. 24 and 25 in particular, it is seen thatthe neck 77 is not threaded over its entire length, but includes asmooth surfaced portion 80 of width equal to the width of the threadedportion 79 thereof. In a further aspect, the outer surface 66 of thesleeve 65 may include a plurality of flats 661 best facilitatinggripping by a tool or the fingers of a surgeon to facilitate therotation of the sleeve 65 and, thereby, movement of the bodies 61, 63toward or away from one another.

As seen in FIGS. 23-25, the retainers 67, 73 have respective openingsdesignated by the respective reference numerals 87 and 89, as well asrespective surfaces 91, 93. The surface 91 tapers from a larger diameteradjacent the wall 95 to a smaller diameter adjacent the wall 96. Thesurface 93 tapers from a larger diameter adjacent the wall 97 to asmaller diameter adjacent the wall 98. The tapers of the surfaces 91 and93 is for the same purpose described hereinabove with regard to theother components of the inventive system, to wit, to facilitateinsertion in the retainers 61, 63 of the tapered surface 107 of thesleeve 101 of a locking sleeve assembly 100. This is seen with referenceto FIGS. 3 and 4, which show two examples of the mounting of a couplerassembly 60 between two rods 10.

As should be understood with particular reference to FIG. 25, when thecoupler assembly 60 is assembled together, the body 63, rod 75 isinserted through the sleeve 65 until the threads 79 thereof may bethreaded onto the threads 85 of the sleeve 65. Similarly, the body 61may be mounted on the sleeve 65 by insertion of the rod 69 thereof andthreading of the threads 71 thereof onto the threads 83 of the sleeve65. Threading of the rod 69 into the bore 81 through the use of thethreads 83 will cause the rod 69 to be advanced into the bore 81.Similarly, threading of the threads 79 of the neck 77 of the body 63onto the threads 85 of the sleeve 65 will cause advancement of the rod75 of the body 63 into the bore 81.

As stated hereinabove, the outer diameter of the rod 75 is smaller thanthe inner diameter of the bore 70 in the rod 69, so that the rod 75 ofthe body 63 may slide within the bore 70 of the rod 69 of the body 61 tothereby facilitate the guidance of inward and outward movements of therespective bodies 61, 63 with respect to one another.

In an important aspect, the unthreaded surface 80 of the neck 77 allowsthe threaded portion 79 of the neck 77 to be threaded past the threadedportion 85 of the bore 81 of the sleeve 65. When this has beenaccomplished, thereafter, the sleeve 65 may be rotated with respect tothe body 63 without reciprocating with respect thereto. Thus, the sleeve65 may be premounted on the body 63 with the threads 85 and 79 beingthreaded past one another so that threads 85 of the sleeve 65 are lyingin overlying relation over the smooth surface 80 of the neck 77.Thereafter, the sleeve 65 may be rotated with respect to the body 63 ina direction causing advancement of the threaded rod 69 of the body 61into the bore 81 with the bore 70 of the rod 69 advancing over therelatively stationary rod 75 of the body 63.

In this way, adjustments of the length of the coupler assembly 60, fromend to end, may easily be accomplished through rotations of the sleeve65.

As best seen in FIGS. 3 and 4, the coupler assembly 60 is mountedbetween two rods 10 with the openings 87, 89 facing either in the samedirection or in opposite directions, as desired. As describedhereinabove, the surfaces 91, 93 are placed in engagement over thetapered surfaces 107 of sleeves 101 forming a part of respective lockingsleeve assemblies 100. Thereafter, lock nuts 103 are threaded over thethreaded portion 111 of the sleeves 101 until the flanges 125 thereofbear against the walls 96 or 98 (FIG. 24) of the respective bodies 61,63. Further threading of the lock nuts 103 on the respective threadedportions 111 of the sleeves 101 will cause pulling of the taperedsurfaces 107 of the sleeves 101 into the respective recesses 91, 93 tothereby tighten the bodies 61, 63 in mounted relation over the lockingsleeve assemblies 100 and thereby the rods 10. Cut portions 62 in therespective openings 87, 89 are provided to allow the sleeves 101 to beinserted into the recesses 91, 93 without having to move the shoulders109 of the sleeves 101 completely past the respective walls 95, 98thereof. Analogous structure to the cut portions 62 shown in FIG. 24 isseen with regard to the reference numeral 222 in FIG. 12 and thereference numeral 182 in FIG. 13 and reference numeral 922 in FIG. 18.

As such, hereinabove, all of the components which form a part of theinventive posterior spinal system have been described in great detail.In light of such description, the examples shown in FIGS. 1 and 7 shouldbe understood to be merely examples of the numerous combinations ofcomponents which may be combined together to mount two smooth surfacedrods 10 in predetermined spaced relation with respect to one another onthe posterior spine to correct the various deformities and conditionsdescribed hereinabove.

With the various components making up the inventive posterior spinalsystem having been described hereinabove, it is believed to beinstructive to describe in detail an example of a method of performingsurgery using the posterior spinal system of the present invention.

In installing a mid-line clamp assembly on the posterior spine betweentwo adjacent smooth surfaced rods, pre-operative planning is undertakenwherein the curved magnitude limits of safe correction and levels offusion are determined according to standard surgical procedures.Mid-line clamps are placed at selected levels throughout the to be fusedsegment and the necessary number and orientation of each component isdetermined.

Exposure, decortication and grafting techniques are performed accordingto standard surgical procedures.

In preparing the site of the surgery, the first spinous process cut ismade in the transverse plane at the base of the inferior articularfacets. A suitable clamp installer is placed on each level to beinstrumented and is used to gauge the second cut to the spinous process.The second cut is parallel to and approximately 0.2 inches posterior tothe anterior surface of the lamina. In the preferred mode of operating,all cuts are executed using a Hall micro E sagittal saw. Prior toremoval of the clamp installer, the required clamp size is determinedtherefrom.

Each appropriate sized clamp for implantation is placed on a suitableclamp holder instrument and is thereafter placed on the respectivevertebra by sliding the inferior clamp shoe under the inferior laminaand dropping in the superior shoe through the superior lamina notch andcinching into place. The clamp holder is then used to maintainapproximation of the clamp halves.

Two smooth surfaced rods 10 of appropriate length to facilitatecorrection and maintenance of the spine are contoured through theutilization of aluminum templates and rod benders. The appropriatenumber of locking sleeve assemblies 100, as determined pre-operatively,are placed on the rods 10 pointing in the proper directions for fixationof the mid-line clamps 20 and couplers 60. Hook bodies 140 are placed onsuitable hook body holders and are then placed on the mid-line clampstuds leaving the hook body holders in place for manipulation of thehook bodies 140 during correction. For this purpose, the holes 142, bestseen in FIG. 22, on the hook bodies 140 are employed.

Lateral correction is achieved by cantilever loading utilizing hook bodyholders to manipulate the hook bodies 140, with a locking sleeveintroducer or surgical slider instrument being used to manipulate thelocking sleeves. Both a surgical rod pusher instrument and lateralapproximator may be used to provide mechanical advantage as needed.Locking sleeves are placed into the hook bodies 140 and are seated withthe locking sleeve introducer instrument, thus maintaining correction.

Locking sleeves are placed in the hook bodies 140, utilizing hook bodyholders, locking sleeve introducers, rod pushers and sagittalapproximators as necessary. The locking sleeves are seated as explainedhereinabove, and any additional amounts of distraction or compressionare now imposed on the system using rod clamps and a distractor. Asuitable locking sleeve cincher instrument is used to fully seat thelocking sleeve and the locking nut is finger tightened. Furthertightening of the locking sleeves and nuts is achieved through the useof a clamp cincher to provide approximately 80% of required clampingforce. Final nut tightening is accomplished through the use of anappropriate wrench.

The system is finally secured through the use of the required number ofcoupler assemblies 60 which are placed on the rods 10 via lockingsleeves assemblies 100 and are tightened onto the rods 10 thereby. Thesleeves 65 of the coupler assemblies 60 are rotated in a desireddirection to move the bodies 61, 63 either toward or away from oneanother to provide and maintain the desired separation between the rods10 and facilitate lamina contact of the bodies to improve stability. Inthis way, the coupler assemblies act as turnbuckles.

Thereafter, the surgical site is closed using standard surgicaltechniques The above described surgical process may be followed withreference to FIG. 1 and the associated figures, since FIG. 1 showsexamples of mid-line clamps 20 and coupler assemblies 60 as assembled ontwo smooth surfaced rods 10.

With reference, now, to the example shown in FIG. 7 and associatedfigures, the technique employed in placing hooks on the posterior spinewill be described in detail.

In a first aspect, pre-operative planning is accomplished and hooksites, curve magnitude and levels of fusion are all determined accordingto standard surgical procedures. The necessary number and orientation ofeach component is also determined thereby.

Thereafter, exposure of the site is accomplished as per standardsurgical techniques.

Thereafter, hook site preparation is performed as per standardHarrington and Cotrel-Dubousset procedures.

Hook placement is performed utilizing hook holders and stabilizers in amanner according to typical Harrington and Cotrel-Dubousset procedures.

Thereafter, two smooth surfaced rods 10 of appropriate length arecontoured through the utilization of rod benders and aluminum templatesto the desired contour of the spinal column. The appropriate number oflocking sleeve assemblies 100 for each rod 10 are placed on each rod 10in a necessary orientation for each hook and coupler site.

Cantilever correction as well as distraction/compression techniques maynow be utilized. Lateral and sagittal approximators as well as rodpushers and distractors are provided to facilitate these correctionmodes. Cotrel-Dubousset correction techniques may be utilized wherenecessary. Upon correction at each nodal site, a locking sleeve will beplaced into the recess in the open backed body of a hook utilizing theappropriate hook holders and locking sleeve assembly introducer orsurgical slider instrument. In the preferred mode of use, lateralcorrection will precede sagittal correction.

Thereafter, locking sleeves are fully seated, utilizing a locking sleevecincher instrument and wrench. Coupler assemblies 60 are placed at theappropriate levels and are distracted or compressed where necessary anddesired to establish and maintain the desired spacing between the rods10. Such distraction or compression enhances structural stability.

Thereafter, closure is as per standard surgical techniques.

Of course, where desired in either of the surgical procedures describedhereinabove, pedicle screws (not shown) may be employed having studssimilar in construction to the studs incorporated in the mid-line clampassemblies as particularly illustrated with reference numerals 31 and 37in FIGS. 11 and 15, as well as with reference numerals 271, 277 and 278in FIG. 14. Thus, such a spinal pedicle screw may be affixed to arespective rod 10 through the use of a hook body 140 as should beunderstood.

Now, the inventive system and examples of methods of use thereof havingbeen described in detail, further preferred details of the individualcomponents will now be set forth.

The two embodiments of mid-line clamp assembly disclosed herein areworthy of discussion.

The inferior and superior shoes of the mid-line clamp assemblies havebeen optimized through cadaver testing, which testing determined theload carrying ability of the lamina structure. The studs are positionedon the respective clamp halves so as to ensure hook body contacts withthe lamina. The head of each stud is flat to minimize lateral profile.As described hereinabove, the small mid-line clamp assembly includes onestud on each clamp half, whereas the large mid-line clamp assemblyincludes two studs on the superior clamp half. It has been found thatthe small clamp may have an inadequate size to permit the placement ofthree studs thereon. If a clamp larger than the small clamp is used,such as, for example, the large clamps 260 illustrated in FIG. 14, threestuds may be included.

Any suitable spinal hook style may be adapted for use with the lockingsleeve assemblies of the present invention by inclusion of a taperedrecess enabling attachment of the tapered recess of the hook to thetapered sleeve of the locking sleeve assembly as described herein. Threesuch styles of hooks which have been adapted with open back and taperedrecess features of present invention are described above as the bifidhook 180, the lamina hook 220 and the Andre hook 200.

Concerning the bifid style hook 180, best seen in FIGS. 9 and 13, thishook has a fork spacing 188. The forks taper in to provide wedging ofthe pedicle and two sizes of shoe that may be provided to accommodatefor varying lamina heights allowing more posterior placement of the hookshoe while minimizing posterior profile. Excessive notching of the facetand lamina would expose the nerve root and cause the unsafe possibilityof striking the nerve root upon insertion.

The lamina hook 220, best seen in FIGS. 10 and 12, is designed to havethe same size shoe as an Edwards Anatomic hook (mentioned in theBackground), except that shorter shoe height is provided to minimizecanal intrusion during insertion.

The shoe of the Andre hook 200, best seen in FIG. 26, may utilize anarrower shoe to allow the placement of two hooks at a single level.

Concerning the locking sleeve assembly 100 and the coupler assembly 60,the radially outwardly extending flange 125 of the lock nut 103 of thelocking sleeve assembly 100 is designed to have a sufficient diameterthat when the locking sleeve assembly 100 is being used to maintain acoupler assembly 60 in place between two adjacent smooth surfaced rods10, when the locking nut 103 is appropriately tightened on the sleeve101, the flange 125 will interfere with the turnbuckle portion 65 termedhereinabove the sleeve of the coupler assembly 60, to thereby preventloosening of the turn-buckle.

Of course, the components described hereinabove as forming an integralpart of the inventive system may be made of any desired materials solong as they exhibit required strength and flexibility as well as beinginert and not causing the body to have a rejection reaction. Forexample, the smooth surfaced rods may be made from cold-worked stainlesssteel which due to the smooth surface configuration exhibits fatigue andflexibility characteristics superior to rods of much larger diameterwhich have threaded or knurled surfaces.

As such, a posterior spinal system has been disclosed in terms of smoothsurfaced rods, a locking sleeve assembly designed to be used to affixall other system components to the rods and in terms of the systemcomponents, including mid-line clamps with hook bodies, hooks, screwswith hook bodies, coupler assemblies and any and all other suitablefixation devices.

Of course, various changes, modifications and alterations in theteaching of the present invention may be contemplated by those skilledin the art without departing from the intended spirit and scope of thepresent invention.

We claim:
 1. A spinal locking sleeve assembly and an elongated spinalrod and another structure for use in a spinal implant system, whereinsaid assembly interconnects the elongated rod with the structure,wherein said structure has a tapered passage therethrough and a sidewalladjacent to a terminus of said passage, said assembly comprising:a) anelongated sleeve having a continuous bore therethrough, said sleevehaving a first end with a tapered outer surface and a b) at least onesplit in said sleeve extending into at least a portion of each of saidfirst and second ends thereof; c) a lock nut having an internalpassageway with threads complementary to the threads of said second end;d) said bore being sized to slidably receive said rod therethrough; e)said tapered outer surface of said sleeve being insertable into saidtapered passage of said structure with said rod in said bore, to form aninterference fit between the two tapered surfaces, and wherein saidpassage includes an open back wherein the open back has a width greaterthan the diameter of said elongated spinal rod.
 2. A spinal lockingsleeve assembly and an elongated spinal rod and another structure foruse in a spinal implant system, wherein said assembly interconnects theelongated rod with the structure, wherein said structure has a taperedpassage therethrough and a sidewall adjacent to a terminus of saidpassage, said assembly comprising:a) an elongated sleeve having acontinuous bore therethrough, said sleeve having a first end with atapered outer surface and a second threaded end; b) at least one splitin said sleeve extending into at least a portion of each of said firstand second ends thereof; c) a lock nut having an internal passagewaywith threads complementary to the threads of said second end; d) saidbore being sized to slidably receive said rod therethrough; e) saidtapered outer surface of said sleeve being insertable into said taperedpassage of said structure with said rod in said bore, to form aninterference fit between the two tapered surfaces, and wherein said locknut is threaded onto said second end of said sleeve until said lock nutengages said sidewall, and wherein further rotation of the lock nutcauses said at least one split to narrow to cause said sleeve tofrictionally grip said rod, to interconnect said rod and structure. 3.The invention of claim 2, wherein said passage is tapered in the samedirection as the taper of said tapered outer surface as placed in saidpassage.
 4. The invention of claim 2, wherein said lock nut includes aradially outwardly extending flange adapted to engage said sidewall ofsaid structure.
 5. The invention of claim 2, wherein said at least onesplit comprises a plurality of circumferentially-spaced splits, one ofsaid splits extending the entire longitudinal extent of said sleeve. 6.The invention of claim 5, wherein said sleeve has a longitudinal axis,said splits being at an oblique angle to said axis.
 7. The invention ofclaim 2, further including a shoulder separating said first and secondends of said sleeve.
 8. The invention of claim 2, wherein said passageis open backed.
 9. The invention of claim 2, wherein said structurecomprises a hook body.
 10. The invention of claim 2, wherein saidstructure comprises a coupler assembly.
 11. The invention of claim 1,wherein said structure comprises a hook having an extending hook shoe.12. The invention of claim 8, wherein said structure comprises a hookbody.
 13. The invention of claim 8, wherein said structure comprises acoupler assembly.
 14. The invention of claim 8, wherein said structurecomprises a hook.
 15. A spinal locking sleeve assembly and an elongatedspinal rod and another structure for use in a spinal implant system,wherein said assembly interconnects the elongated rod with thestructure, wherein said structure has a tapered passage therethrough anda sidewall adjacent to a terminus of said passage, said assemblycomprising:a) an elongated sleeve having a continuous bore therethrough,said sleeve having a first end with a tapered outer surface and a secondend with a securing means thereon; b) at least one split extending intosaid sleeve; c) a lock means having an internal passageway with a matingsecuring means complementary to the securing means on the sleeve; d)said bore being sized to slidably receive said rod therethrough; e) saidtapered outer surface of said sleeve being insertable into said taperedpassage of said structure with said rod in said bore, to form aninterference fit between the two tapered surfaces, and wherein saidpassage includes an open back wherein the open back has a width greaterthan the diameter of said elongated spinal rod.
 16. A spinal lockingsleeve assembly and an elongated spinal rod and another structure foruse in a spinal implant system, wherein said assembly interconnects theelongated rod with the structure, wherein said structure has a taperedpassage therethrough and a sidewall adjacent to a terminus of saidpassage, said assembly comprising:a) an elongated sleeve having acontinuous bore therethrough, said sleeve having a first end with atapered outer surface and a second end with a securing means thereon; b)at least one split extending into said sleeve; c) a lock means having aninternal passageway with a mating securing means complementary to thesecuring means on the sleeve; d) said bore being sized to slidablyreceive said rod therethrough; e) said tapered outer surface of saidsleeve being insertable into said tapered passage of said structure withsaid rod in said bore, to form an interference fit between the twotapered surfaces, and wherein said lock means is secured onto the secondend of said sleeve so that said lock means engages said sidewall, andwherein this securement of the lock means causes said at least one splitin the sleeve to narrow to cause the sleeve to frictionally grip saidrod, to interconnect said rod and structure.
 17. The invention of claim15, wherein said passage is tapered in the same direction as the taperof said tapered outer surface as placed in said passage.
 18. Theinvention of claim 16, wherein said lock means includes a radiallyoutwardly extending flange adapted to engage said sidewall of saidstructure.
 19. The invention of claim 15, wherein said at least onesplit comprises a plurality of circumferentially-spaced splits, one ofsaid splits extending the entire longitudinal extent of said sleeve. 20.The invention of claim 19, wherein said sleeve has a longitudinal axis,said splits being at an oblique angle to said axis.
 21. The invention ofclaim 16, further including a shoulder separating said first and secondends of said sleeve.
 22. The invention of claim 16, wherein said passageis open backed.
 23. The invention of claim 15, wherein the securingmeans on the sleeve and the mating securing means on the lock means aremating threads.
 24. A spinal locking sleeve assembly and an elongatedspinal rod and another structure for use in a spinal implant system,wherein said assembly interconnects the elongated rod with thestructure, wherein said structure has a tapered passage therethrough anda sidewall adjacent to a terminus of said passage, said assemblycomprising:a) an elongated sleeve having a continuous bore therethrough,said sleeve having a first end with a tapered outer surface and a secondthreaded end; b) at least one split in said sleeve extending into atleast a portion of each of said first and second ends thereof; c) a locknut having an internal passageway with threads complementary to thethreads of said second ends; d) said bore being sized to slidablyreceive said rod therethrough; e) said tapered outer surface of saidsleeve being insertable into said tapered passage of said structure withsaid rod in said bore, to form an interference fit between the twotapered surfaces, and wherein said lock nut has an end face, and whereinthe lock nut is threaded onto said second end of said sleeve, andwherein said lock nut is axially movable relative to the structure alongsaid second end of said sleeve until said end face of the lock nutengages said sidewall, and wherein further rotation of the lock nutcauses said at least one split to narrow to cause said sleeve tofrictionally grip said rod, to interconnect said rod and structure. 25.A spinal locking sleeve assembly and an elongated spinal rod and anotherstructure for use in a spinal implant system, wherein said assemblyinterconnects the elongated rod with the structure, wherein saidstructure has a tapered passage therethrough and a sidewall adjacent toa terminus of said passage, said assembly comprising:a) an elongatedsleeve having a continuous bore therethrough, said sleeve having a firstend with a tapered outer surface and a second end with a securing meansthereon; b) at least one split extending into said sleeve; c) a lockmeans having an internal passageway with a mating securing meanscomplementary to the securing means on the sleeve; d) said bore beingsized to slidably receive said rod therethrough; e) said tapered outersurface of said sleeve being insertable into said tapered passage ofsaid structure with said rod in said bore, to form an interference fitbetween the two tapered surfaces, and wherein said lock means has an endface, and wherein the lock means is securable onto said second end ofsaid sleeve, and wherein said lock means is axially movable relative tothe structure along the second end of said sleeve until said end face ofsaid lock means engages said sidewall, and wherein further advancementof the lock means causes said at least one split in the sleeve to narrowto cause the sleeve to frictionally grip said rod, to interconnect saidrod and structure.